·a-ryt o ~aVolume 63 · Number 4 ’ 2005

Arnoldia (ISSN 004-2633; USPS 866-100) ispublished quarterly by the Arnold Arboretum ofHarvard University. Periodicals postage paid atBoston, Massachusetts.

Subscriptions are $20.00 per calendar year domestic,$25.00 foreign, payable m advance. Single copies ofmost issues are $5.00 (plus postage); the exceptionsare 58/4-59/1 (Metasequoia After Fifty YearsJ and54/4 (A Source-book of Cultivar Names), which are$10.00. Remittances may be made m U.S. dollars,by check drawn on a U.S. bank; by internationalmoney order; or by Visa or Mastercard. Send orders,remittances, change-of-address notices, and all othersubscription-related commumcations to Arnoldia,Arnold Arboretum, 125 Arborway, Jamaica Plam,Massachusetts 02130-3500. Telephone 617.524.1718;facsimile 617.524.1418; e-mail arnoldia@arnarb.harvard.edu.

Postmaster: Send address changes toArnoldiaThe Arnold Arboretum125 ArborwayJamaica Plam, MA 02130-3500

Karen Madsen, EditorMary Jane Kaplan, CopyeditorLois Brown, Editorial AssistantAndy Winther, Designer

Editorial Committee

Phyllis AndersenRobert E. CookPeter Del Tredici

Jianhua LiRichard Schulhof

Stephen A. SpongbergKim E. Tripp

Copyright © 2005. The President and Fellows ofHarvard College

Page2 Against All Odds: Growing Franklinia

in BostonPeter Del Tredici

8 A Silver Anniversary: The Fall PlantDistribution and Sale, 1980-2005

9 The Dove Tree: A Long Journey WestRichard Schulhof

11 I Ilex pedunculosa: The Longstalk HollyPhyllis Andersen

13 ’Yoshino’: An Outstanding Cultivar of theJapanese CedarKim E. Tripp

15 5 Microbiota decussata: A Versatile Conifer

Nancy Rose

17 7 Chionanthus retusus: The Chinese

FringetreePeter Del Tredici ~ Jianhua Li

19 9 Beach Plum: A Shrub for Low-Maintenance

LandscapesRichard H. Uva ~ Thomas H. Whitlow

21 1 Calycanthus chinensis: The ChineseSweetshrub

Jianhua Li & Peter Del Tredici23 Rhus trilobata: Worthy Plant Seeks

Worthy NameNancy Rose

26 Demystifymg DaphnesBob Hyland

29 Index to Volume 63

Front cover: The flowers of Stewarna ovata forma

grandiflora, accession number 18244-B, received fromT. G. Harbison of Highlands, North Carolma, in 1925.This specimen is unusual in producmg five-petaledflowers with either purple or nearly white anther fila-ments, and occasionally chimeric flowers with both.Photograph by Peter Del Tredici

Inside covers: A photo gallery of plants to be offered onSeptember 18, at the Arboretum’s 25th fall plant sale.See list of photographers on page 32.

Back cover: The graceful fruit of the longstalk holly,Ilex pedunculosa. Photograph by Ethan W. Johnson.

Against All Odds: Growing Franklinia in Boston

Peter Del Tredici

he year 2005 gives the Arboretum anexcuse to celebrate two of its most his-torically significant plants: it marks thecentennial of the Franklinia alatamaha located

along Chinese Path, on the southwest slope ofBussey Hill. Two specimens, growing side byside, were propagated in 1905 as cuttings froma tree received by the Arboretum in 1884. Sincethen, the plants have become giant shrubs thatsprawl across the landscape, taking root wherev-er their branches touched the ground. This "self-layering" habit of Franklinia is an important

part of its growth strategy and gives the plantsan air of dynamism that suggests they will havemoved to a completely different part of the Arbo-retum by the time of their next centennial.The larger of the two plants (#2428-3-B) is

now 21 feet (6.3m) tall by 53 feet ( 16m) wide andhas eight more-or-less vertical "trunks" greaterthan 5 inches (12cm) in diameter (the largest is 7inches, or 18cm). The smaller plant (#2428-3-A)is also 21 feet tall but just 30 feet (9m) wide, andhas six stems larger than 5 inches in diameter.In the ranks of monumental trees, these are not

Franklima alatamaha, # 2428-3-B, at the Arnold Arboretum.

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The spectacular flower of Franklinia.

impressive dimensions, but they are enough toplace them among the largest Franklinias any-where in the world. More important, they are theoldest Franklinias of known, documented lin-eage. To put it another way, we know where the

plants came from and when, which is more thanmost people can say about their Franklinias.The title of "oldest documented Franklinia"

was bestowed on the Arboretum’s plants in 2000after a two-year survey of cultivated Frankliniasthroughout the world that was conducted byHistoric Bartram’s Garden in Philadelphia.’ Toappreciate the significance of this finding, wemust review the plant’s colorful history. Thespecies was discovered in southeast Georgia,along the Altamaha River near Fort Barrington,on October 1, 1765, by John Bartram and hisson William. The plant was not in flower atthe time, so its identity remained uncertain.William returned to the area in 1773 and pro-duced a beautiful illustration of the plant inflower that he ranked as being "of the first orderfor beauty and fragrance." In 1776, William was

able to collect seed from the plants, which hetook back to Philadelphia. Several other collec-tors later visited the Bartram’s Franklima site

along the Altamaha River, the last being theEnglish nurseryman John Lyon in 1803.2 Sincethen, no one has reported finding Frankliniagrowing in the wild.3 .3The species was first described and given

the name Franklinia alatamaha in 1785 byWilliam’s cousin Humphry Marshall in hisgroundbreaking book, Arbustum Americanum:The American Grove. William’s own descrip-tion of his encounter with Franklinia in the wilddid not appear until 1791, when he publishedTravels after a long series of delays. Unfortu-nately Bartram’s very American name did nottake hold in Europe, where botanists chose torefer to Franklinia as Gordonia pubescens.4 Thisname stuck until 1889, when Sargent changedit to Gordonia altamaha.5 It wasn’t until after1925 that Humphry Marshall’s original namefor the plant, Franklinia alatamaha, was widelyrecognized by botanists as legitimate.6

4

William sowed the Franklinia seedhe had collected shortly after hisreturn to Philadelphia in January 1777,and they germinated soon after. Theresultmg plants produced their firstflowers four years later, in 1781, andtheir first seed in 1782.’ On August 16,1783, William wrote to Linnaeus thathe had raised a total of five Franklinia

seedlings-two he sent to France andtwo he planted in his own garden,which were currently flowering and"full of seed nearly ripe."8

In November 1831, William Wynne,the foreman at Bartram’s Garden,reported that one of the original seed-lings was fifty feet tall,9 and in 1832,the botamst Constantine Rafinesquevisited the garden and described aspecimen that was "nearly 40 feethigh."’° In 1846, D. J. Browne noteda Franklinia in Bartram’s garden thatwas "fifty-two feet in height, with atrunk three feet and nine inches incircumference [which equals a diam-eter of 14 inches]."" Seven years later,Thomas Meehan measured one ofBartram’s Franklinias at "about thirtyfeet high [with] a diameter of from

Thomas Meehan (1826-1901). ).

The Arboretum’s original accession card for the Franklinia alatamaha(received as Gordonia pubescens) from Thomas Meehan m December1884

This drawmg appears in The Standard Cyclopedia of Horticulture,rev. ed., 1916, with this caption : "A tender tree bound m branches ofhemlock. The protected tree is a specimen of gordoma [Frankhnia] about10 feet high, at Arnold Arboretum, Boston.

"

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nine to twelve inches." He went on tonote that "the finest specimen latelyblew off in a gale,"’z a statement thatclearly indicates that only one of Bar-tram’s original seedlings-the smallerof the two-was alive in 1853.The last measurement of the origi-

nal trees was in 1890, by Joseph Mee-han, Thomas’ younger brother, whoreported in Garden and Forest:

This tree was supposed to be dead, andin fact it did die to the ground, but ona recent visit to it I observed a suckerof several feet m length from a portionof the stump beneath the ground.

In this same article, Meehan reportedthe existence of a 25-foot-tall speci-men of Franklinia growing in thegarden of William De Hart in Phila-delphia that was "raised by layeringa branch of the original tree in Bar-tram’s Garden."13 Unfortunately thistree no longer exists.The two plants that grew in Bar-

tram’s garden were a ready source ofFranklinia seed-indeed, the onlysource-and they were distributedby William and later by his nephew,Robert Carr.’4 As Franklinia becamemore common in the Philadelphiaarea, a number of local nurseries

began propagating it. Foremostamong the early propagators wasThomas Meehan, who had immi-grated to the United States in 1848and worked as the gardener at Bar-tram’s Garden before establishing his own nurs-ery in Germantown in 1853.’S In that same year,Meehan published The American Handbook ofOrnamental Trees in which he described thecultivation and propagation of Franklinia: "Itseems to thrive best in a light rich loam, con-tiguous to moisture; and may be propagated byeither seeds or layers."’~ During the 1870s and80s, the Arboretum’s first director, C. S. Sargent,worked closely with Meehan to save Bartram’shouse and what was left of the garden fromdestruction, a goal that was accomplished in1891 when the property officially became partof the Philadelphia park system." 7

C. E. Faxon’s illustration of Franklima alatamaha (Tab XXII) from volumeone of Silva of North America by C. S. Sargent (1890).

It was therefore appropriate that ThomasMeehan should have donated a Franklinia plantto the Arnold Arboretum. It was accessionedunder #2428 as Gordonia pubescens in Decem-ber 1884. Meehan’s donation was most likelypropagated from a specimen of Franklinia grow-ing in his nursery in Germantown, just outsidePhiladelphia. Sargent mentions this tree in theFranklima entry of the first volume of Silva ofNorth America where he published a beautifulillustration of it.l8 The specific technique thatwas probably used to propagate this plant wasdescribed by Thomas Meehan’s younger brotherJoseph in Garden and Forest: "The tree can be

6

Frankhma’s fall fohage.

increased by layering. If good soil be placed aboutit, and the layer not disturbed for two years, astrong, well-rooted plant results."’9

Franklinia at the Arnold Arboretum

In 1889, Sargent announced in the pages of Gar-den and Forest that:

Gordonia pubescens has flowered this year at theArnold Arboretum, growing in the open ground.The plant was bent over and covered with soil lastwmter. Though not hardy at Boston, it might dowell when tramed agamst a sheltering wall. A fewof its beautiful flowers would well repay a littletrouble and care.2°

The following year, in the September 24, 1890,issue of Garden and Forest, the Arboretum’sdendrologist, J. G. Jack, reported that Frankliniawas again flowering at the Arboretum, and in1893 he elaborated on the technique used toprotect the plant in winter:

[A]t the Arboretum, after growmg m its presentposition for about eight years, it is a several-stemmed shrub eight or ten feet high. Moreover, it

is necessary every autumn here to bend its stemsover, to as near the ground as possible, and protectthem from the rigors of wmter with leaves, soilor other protecting matemal. After pegging thebranches down, the best protection is affordedby putting dry leaves over and among them, andthen covering the whole with soil thrown upm the form of a little mound, so as to shed therams. It might pass the winters without such pro-tection if planted m the shelter of some warmwalls. In any case, it is well worth any extracare bestowed upon it ... It may be propagated bylayers or cuttmgs.2’

Jack’s reference to the propagation of Frank-linia by cuttings was later corroborated by Sar-gent, also in the pages of Garden and Forest,where he noted:

Two or three plants of Gordoma altamaha arenow in flower in the Arnold Arboretum. The

plants are only about three feet high and are fromcuttmgs taken in July, 1891. They have stood outtwo wmters without protection and nothmg butthe new growth was killed.22

Indeed, a check of the Arborctum’s recordsshows that cuttings from #2428 were taken inJuly 1891 and given a new accession number,2428-1. And it’s a good thing, too, because theoriginal plant from Meehan died in 1896. Cut-tings from #2428-1 were successfully rooted inJuly 1900, on July 5, 1905, and finally in 1908.The plants from both the 1905 and 1908 cuttingswere given the accession number 2428-3. Two ofthe plants from this third-generation accessionof Franklinia are still growing on Bussey Hill,one hundred and twenty-one years after theirarrival at the Arnold.The decision to plant Franklinia on the

southwest slope of Bussey Hill was based onthe knowledge-gained from experience-thatthis was one of the best locations for growingplants in the Arboretum’s 260 acres. Over theyears, this area (now known as "Chinese Path")has consistently provided Arboretum staff witha perfect location for growing plants whose har-diness is either marginal or unknown. The soil,which is deep and relatively free of stones, pro-vides an excellent balance of moisture retentionand drainage, and the mid-slope location givesprotection from both the cold winter winds andthe unpredictable frosts of spring and fall.The Arboretum’s early experiments with cul-

tivating Franklinia were primarily focused on

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its hardiness. From the perspective of 120 years’hindsight, however, the plant’s susceptibility todisease-especially from the wilt-causing fun-gus Phytophthora cinnamoni-appears to be amore critical problem. This pathogen is particu-larly troublesome in heavy, wet soils, but evenwhere drainage is not an issue, Franklmia hasthe well-deserved reputation of being difficultto keep alive-a "miffy" plant, to use an Englishhorticultural term. A second factor that makesFranklinia tricky to grow is its requirement foracid soil-with a pH between 5 and 6-an obser-vation that was not documented until 1927.23

This reconstruction of Franklinia’s long historyat the Arboretum makes it obvious that muchof the horticultural knowledge that we take forgranted today exists only because of the workof persistent staff members constantly push-ing the limits of what they could cultivate. TheFranklinia growing today on Bussey Hill area living legacy to the untiring efforts of JohnBartram and his son William, Thomas Meehan,Charles Sargent, and John Jack. Indeed, on acrisp fall day m October, a knowledgeable visi-tor to the Arboretum can sense the presence ofthese men amidst the stunning display of purewhite flowers and rich crimson foliage. Theywere able to accomplish great things becausethey believed in the importance of their workand stuck with it through all kinds of adver-sity. Without their concerted efforts, Frankliniamight never have survived into the twenty-firstcentury, let alone come into flower on BusseyHill in the year 2005.

Endnotes

’ Historic Bartram’s Garden. 2000. Franklinia Census.

Special publication of the John Bartram Association2 F. Harper, ed. 1958. The Travels of Wilham Bartram,

Naturahst’s Edition New Haven: Yale UmversityPress; J. Ewan. 1968. Wilham Bartram. Botanicaland Zoological Drawings, 1756-1788 Philadelphia:American Philosophical Society.

3 F. Harper and A. N. Leeds. 1937. A supplementarychapter on Frankhma alatamaha. Bartonia 19: 1-13.

4 J. Fry. 2000. Franklmia alatamaha, a history of that"very curious" shrub. Bartram Broadside, Spring2000.

5 C. S. Sargent. 1889. Gordoma pubescens. Garden andForest 2(96): 616

6 C. E. Kobuski. 1951. Studies in the Theaceae, XXI: the

species of Theaceae indigenous to the Umted States.Journal of the Arnold Arboretum 32: 123-138.

’ H. Marshall 82/G~: 6. 1785 Arbustum Amencanum: theAmencan Grove. Joseph Crukshank: Philadelphia.

J. J. T. Fry. 2003. More on Frankhmas The AmericanGardener

W. Wynne 1832. Gardener’s Magazme (London) 8:272-277.

10 C. S. Rafinesque. 1832. New plants from Bartram’sBotamc Garden. Atlantic journal 1, 2: pp 79-80.

" D. J. Browne 1846. Trees of America. Natme andForeign New York. Harper Brothers.

’z T. Meehan. 1853 The Amencan Handbook ofOrnamental Trees. Philadelphia: Lippincott, Grambo,and Co.

’3 J. Meehan. 1890. Gordoma Altamaha (pubescens/.Garden and Forest 3/133~: 445. See also J. Meehan.1888. Garden and Forest 1(36) : 429.

" J. Fry. 1996. Bartram’s garden catalogue of NorthAmerican plants, 1783. Journal of Garden History16.

’S L. H. Bailey. 1916. The Standard Cyclopedia ofHorticulture, pp. 1587-88. New York: The MacmrllanCo.

’~ T. Meehan. 1853. The Amencan Handbook ofOrnamental Trees. Philadelphia: Lrppmcott, Grambo,and Co.

" J. Meehan. 1897. In Bartram’s Garden. Meehans’Monthly 7’ 50.

’n C. S. Sargent. 1890. Silva of North Amenca 1~ 45-4GHoughton Mifflin, Boston Frankhma is classified asGordonia altamaha in this work.

1v J. Meehan. 1888. Garden and Forest 1(3G~: 429.z° C. S. Sargent. 1889. Notes. Garden and Forest 2(84)480

z’ --- 1893. Noteworthy late-flowering shrubs.Garden and Forest 6(295): 436-437.

22 C. S. Sargent 1884. Notes. Garden and Forest 7(344):390.

~ F. V. Coville. 1927. The effect of alummum sulfate onrhododendrons and other acid-soil plants. SmithsonianInstitution 1926 Annual Report, Washington, D.C.,pp.369-382.

AcknowledgmentsThe author would especially like to thank Joel T.Fry, Curator of Historic Collections at Bartram ’sGarden, for directing him to the articles in Garden andForest describing the Arnold Arboretum’s efforts atcultivating Frankhnia.

Peter Del Tredici is a senior research scientist at theArnold Arboretum.

A SILVER ANNIVERSARYThe Fall Plant Distribution and Sale, 1980-2005

In 1980 the flyer for the Fall Plant Distribution and Sale -the

Arboretum’s first-noted that many of the species being offeredwere rarely seen even in the botanical gardens of North America.Members were encouraged to take their time and browse carefully,"so that you don’t overlook those rare gems seldom found in privategardens." That advice is just as apt today, as many of these unusualplants remain hard to find.

In honor of the sale’s silver anniversary, Arnoldia asked notable plantpeople to contribute comments on their favorites from the list of plantsat this year’s sale. Photographs of many of the plants to be offered aredisplayed on the inside front covers as well as on this page.

The Dove Tree: A Long journey West

Richard Schulhof

hether for a plant collector ora gardener with a taste for theW remarkable, there is much to

recommend in a tree that combines acurious beauty with a storied past. Forthose interested in the history of plantintroduction, few species conjure moreimages of turn-of-the-century explora-tion than the famed dove tree (Davidiainvolucrata). And for horticulturists,the first encounter with the dove treeis often like one’s first taste of cham-

pagne, initially peculiar to the palate butgreatly prized by the end of the glass.

It was like that for me. The occasionwas a student field trip on a blusteryspring day in Boston, Massachusetts;the location was the Arnold Arboretum.After a long search for the tree, we werea little disappointed with our first glimpse ofa specimen that was surprisingly inconspicu-ous from a distance-the many white, flutteringbracts might have been mistaken for leaves witha pale underside. Closer examination, however,revealed inflorescences of exquisite complex-ity. Uneven pairs of improbable greenish-whitebracts ~"doves") hung dramatically from malt-ball-sized globes of a wonderful chocolatebrown. With my hand lens I made out scores ofsmall male flowers covering these balls like theflorets of a dandelion; near the center stoodthe single female flower. I had never seen any-thing quite like it.

But the experience was especially memorablebecause we believed the tree before us was not

just any dove tree but a historic specimen grownfrom seed collected by Ernest H. Wilson, thecelebrated plant explorer most closely associatedwith the Arnold Arboretum. Ironically, how-ever, the tree in question-the Arboretum’s bestspecimen-results not from a Wilson expeditionbut from that of an earlier plant explorer, Frenchmissionary Pere Paul Guillaume Farges.

An outstandmg specimen of Davidia mvolucrata var. vilmonniana, m~11 hkhhood the oldest m North America, accession #5159, resides onBussey Hill’s Chmese Path.

I was familiar with the story of Wilson andthe dove tree, having recently read Stephanne B.Sutton’s marvelous biography of the Arboretum’sfounding director, Charles Sargent. In 1869, thespecies was first discovered by French mission-ary Pere Armand David in Sichuan Province,near the Tibetan border. Described and namedafter its discoverer in 1871, the Davidia wassubsequently sighted by Augustine Henry, anEnglish physician with a great passion for bot-any then stationed in China. In 1893, he wroteenthusiastically, "Davidia is worth any amountof money. I saw only one tree of it, but doubt-less there are others in the district ... Davidiais wonderful." /I

Sir Harry Veitch of the prominent Veitch Nurs-ery in Chelsea, England, read Henry’s encomiumand resolved to be the first to offer the heraldednew species commercially. He hired Wilson,then a twenty-two-year-old horticulturist, totravel to China, giving him clear instructions:"The object of the journey is to collect a quan-tity of seeds of a plant (Davidia) ... This is theobject-do not dissipate time, energy or money

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on anything else." Beginning in the spring of1900, Wilson, working from a map provided byHenry, searched a large area of central Chinaonly to discover that the one tree of knownlocation had been cut for lumber. Undeterred, heeventually found several fruiting trees, and hesent hundreds of seeds back to England. The firstplant came into bloom at the Veitch Nursery in1911. However, unbeknown to both Wilson andVeitch, Pere Farges had in 1897 sent 37 seeds tothe arboretum of Maurice de Vilmorin in LesBarres, France. In 1899, one of those seeds ger-minated and the resulting tree bloomed in 1906.So even though Wilson could claim responsibil-ity for broadly distributing the dove tree, thanksto the large quantities of seed he had gathered,the credit for introducing the first specimen tothe west belonged to Farges. Smarting from theloss of greater glory, Wilson wrote, "After mysuccessful introduction of Davidia in 1901, andits free germmation in 1902, I had yet one littlecup of bitterness to drain."

"

It is from the one plant germinated fromFarges’ seed that the outstanding specimenat the Arnold Arboretum (accession #5159*A~originated. The plant, a rooted layer, wasobtained by Charles Sargent and planted at theArboretum in 1904. Injured by severe cold earlym life, the tree resprouted from its base to formthe multi-stemmed specimen we know today.When it bloomed for the first time in 1931, thenArboretum director Oakes Ames, writing in theArboretum’s Bulletin for Popular Information,declared that the specimen was notable more forits botanical novelty than for its beauty:We are told that in its native land, when ladenfrom top to bottom with enormous white floralbracts, some of them attammg a length of eightmches or more, D. mvolucrata presents a wonder-ful aspect. But from an aesthetic pomt of view ithas httle to recommend it. Its claim to a place inthe garden rests on the bizarre form rather thanthe beauty of the mflorescence.

If he could see the fully mature specimen oftoday, Oakes Ames might very well revise hisopinion. Now over 30 feet in height, the treein bloom is without question an outstandingfeature of the Arboretum’s spring landscape(remember, though, the dove tree is an alternate-year bloomer). You can usually find it in full

The distmctme bark of the dove tree

flower on or about Lilac Sunday, perched on thewest-facing slope of Bussey Hill along ChinesePath near several other spectacular specimensof similar vintage. Interestingly, a few feet awaygrows a dove tree that originated from the seedcollected by Wilson for the Veitch Nursery andsent to the Arboretum as a sapling in 1911. Asomber reminder of failed expectations, the Wil-son specimen (accession #14473*A) resides in theshade of stewartias and has never attained thephysical prominence of its nearby neighbor. Likemost dove trees in cultivation, both specimensare of the botanical variety Davidia involucratavar. vilmoriniana, which differs from the speciesin having smooth rather than felted leaves.

Still rare in gardens, Davidia is unrivaledamong hardy trees for historical, botanical, andhorticultural distinction. More than a one-seasonornament, it offers attractive mottled, reddish-gray bark along with three- to five-inch leavesthat are a bright green and usually free of pestsor disease. The large round fruits, roughly one-and-one-half inches in diameter, dangle singlyand often persist into the winter. Althoughonce established it is hardy to USDA zone 6,young plantmgs may require some protection inextreme winters. Please note that if you plant aseedling from the Arboretum plant sale, you willwait up to ten years before seeing a bloom. Yetaccording to E. H. Wilson, the flowers of "themost interesting and beautiful of all trees of thenorth temperate flora" are well worth the wait.

Richard Schulhof is deputy director of the ArnoldArboretum.

Ilex pedunculosa: The Longstalk Holly

Phyllis Andersen

In the fall of 1892, during his first plant col-

Ilecting trip to Japan, Charles Sprague Sargentadmired a distinctive holly growing alongthe Nagasendo Highway, the famous mountainroad connecting Kyoto to Edo (now Tokyo). Hefound the plant growing both in the wild and inthe gardens of local inns, sometimes as a shrubonly two to three feet high and sometimes asa well-formed tree as tall as twenty to thirtyfeet, with a narrow, round-headed top. Its ovalleaves were a lustrous, dark green. But its mostdistinctive feature was its long flower stems,or peduncles, which in the early fall droopedunder the weight of bright red fruit, not unlikethe stems of fruiting cherry trees.

The plant that had so impressed Sargent wasIlex pedunculosa, the longstalk holly, firstdescribed for publication by the Dutch botanistFriedrich Anton Wilhelm Miquel in 1868. Itsaffinity with the hollies of New England made itof particular interest to Sargent, who was com-mitted to researching the similarities betweenthe floras of eastern Asia and eastern NorthAmerica. The plant’s appeal was further enhancedby Sargent’s desire to add plants of significantornamental value to the Arnold Arboretum’scollection. Later Sargent hired the British plantexplorer E. H. Wilson to further pursue the studyof Asian flora, and in 1907 Wilson sent seeds ofI. pedunculosa from China back to Boston.

With lustrous leaves, bnght red frmt, and dependable hardmess throughout zone 5, the longstalk holly is abroadleaf evergreen that fewm New England can nval

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E. H. Wilson photographed this 25-foot-tall longstalk holly in China, 1909.In cultivation the plant attams httle more than half that helght

The first plants propagated from this seedwere set out on the Arboretum’s Hickory Path,where their ornamental qualities and hardinesswere evaluated for many years. Having per-formed well at that site, they were moved in1970 to an area near the Arboretum’s administra-tion building, where they still form a distinctivepart of the setting.

The evergreen leaves of Ilex pedunculosa areoval in shape, one to three inches long and three-fourths to one-and-one-quarter inch wide. Theylack the spines so characteristic of the Americanholly (I. opaca) and the European holly (I. aqui-folium). Several writers have noted the leaves’

resemblance to those of mountainlaurel (Kalmia latifoliaJ; Sargent,on the other hand, compared themto those of "our wild cherry." Inthe Boston area, the plant produ-ces inconspicuous white flowersin mid June. The bright red berries,or drupes, as they are called, areoften as large as those of I. aqui-folium, nearly one inch long andone-quarter inch in diameter. Theyappear in early fall and persist onthe plant throughout the season ifnot eaten by the birds.The branching pattern of the

longstalk holly is generally up-right, becoming more open asthe plant matures. While plantsin the wild can attain up to 30feet in height, they are smaller incultivation, reaching at most 15feet. Like all hollies, Ilex pedun-culosa prefers a well-drained,slightly acidic soil and thrives inpartial shade. It has few disease orpest problems. In common withother hollies, it is dioecious, hav-ing male and female reproductivestructures on separate plants; fora good fruiting display on femaleplants, grow a small male plantin the same general area. (A ratioof one male to up to six femalesis recommended.) /Having observed that in Japan

llex pedunculosa was tound at high elevationsthat were subject to "excessive winter cold," /I

Sargent hoped that the plant would thrive inNew England, where the traditional Englishand American hollies are prone to winter

injury. His hopes were fulfilled: I. pendun-culosa is dependably hardy through USDAzone 5 and has survived severe winters at theArnold Arboretum better than many otherbroadleaved evergreens.

Phyllis Andersen is a landscape historian and instructorin the Landscape Institute of the Arnold Arboretum. Shewas the director of the Arboretum’s Institute for Cultural

Landscape Studies.

‘Yoshino’: An Outstanding Cultivar ofthe Japanese Cedar

Kim E. Tripp

undreds of exceptional conifers exist,

but one among them stands out: a plantthat combines great beauty and diver-sity of form with ease of propagation and toughadaptability. I refer to Cryptomeria japonica, orJapanese cedar.

Japanese cedar is a monotypic genus nativeto Japan and southern China. In Japan, it hasbeen grown and selected for hundreds of yearsas an important forestry crop, a valuable orna-mental, and a bonsai subject. Revered plantingsof Japanese cedar, or sugi, surround several ofthe oldest monastery temples. Many of themare over 300 years old and reach well over 100feet in height, with trunk diameters of 10 feet.But these massive trees bear little resemblanceto the average Japanese cedar on this continent.Nor are these venerable specimens similar to theJapanese cedars often seen languishing in estab-lished landscapes. In North America the oldestspecimens are usually seedlings that have agedinto thinning, gangly individuals. They do notrepresent the handsome forms now available,and unfortunately, they have given Japanesecedar an undeserved reputation for tattiness.The "classic" Japanese cedar, Cryptomeria

~aponica var. japomca, takes on a loosely conical,semiformal shape and can reach heights of 50 to80 feet. The short, flexible, somewhat incurvedneedles give the foliage a soft, refined appear-ance and an easily handled texture. (Most peoplebegin unconsciously stroking the branches ofJapanese cedar within minutes of standing nextto it.) As it matures, C. japonica var. japonicaand related types (including ’Yoshino’) resembletightly knit, forest-green clouds billowing upfrom the ground. However, this characteristicvaries greatly among its many cultivars, whichdiffer so much from one to another that theyhardly seem to be the same species.

Japanese cedar is hardy throughout zones6 to 9-even in mountainous areas and hot

regions of the eastern coastal plain and pied-mont. It prefers a rich, deep, acidic soil, but ithas performed well in many soil types through-out the country. One of its great attributes is its

range of adaptability, extending from the cool,moist Northwest to the hot, wet Southeast. Itprefers higher soil moisture than many otherconifers and suffers during extended dry periods.Its root system is a vigorous, fibrous mass, andeven large trees transplant readily with minimalbrowning and dieback if adequate water is regu-larly provided following transplanting.

Like almost all conifers, Japanese cedar needsfull sun for rapid growth, but it also grows wellin partial shade. Deep or constant shade, how-ever, will lead to thinning and interior dieback.Avoid planting Japanese cedars in exceptionallywindy sites, too, especially in borderline cold-hardiness areas where excessive winter bronzingmay be a problem. Partial shade will minimizewinter bronzing.

Japanese cedar is a problem-free plant withone exception: Stressed plants can be suscep-tible to the fungus Phyllosticta aurea (redfire/.It causes foliage to die and branches to turn abright reddish brown. It generally attacks olderfoliage on individual branches first, then-insevere cases-progresses throughout the treeuntil only the actively growing tips remaingreen. However, susceptibility is highly vari-able among cultivars, and ’Yoshino’ is one ofthe most resistant.Cold can be another of Japanese cedar’s adver-

saries. From time to time, late spring freezes-or fall freezes on actively growing, unhardenedimported plants-will kill the soft tip growthof the branches. Happily, this is never seriousbecause it has a wonderful ability to regrowafter dieback or cutback. (I have seen a 4-foot-tall plant of ’Benjamin Franklin’ reduced to 4inches by a large mower twice in three months;the unrepentant operator of the mower dubbed

14

it "the bionic plant.") Frost or freezedamage to soft tip growth is easilydifferentiated from the symptoms ofredfire fungus. Redfire usually pro-gresses from older to younger tis-sue along a branch and up the tree.Insects are seldom a problem. Sincebagworms, which plague Leylandcypress in some areas, are not nor-

mally a pest of Cryptomeria, the full-size forms of Japanese cedar makean excellent alternative to Leylandcypress.Almost all forms of Japanese cedar

can be propagated easily from cut-tings, which are best taken fromNovember through February but willroot at almost any time of year if

mature, hardened wood is available.Full-size cultivars like ’Yoshino’ will

usually root even if no visible maturewood is available (albeit more slow-ly/, but avoid cutting during activeflushes of growth. Wound cuttingsminimally and treat them with mod-erate concentration of rooting hor-mones and place them under mist. (Inwinter, bottom heat can help.) As onemight expect in a hydrophilic plant, itroots faster at higher mist frequenciesthan those used for other conifers.The cultivar ’Yoshino’ is a full-

sized form that will reach 50 feet

quite rapidly and retain a uniform,. 1 11 . ~ I ~ I . I I

-=>0>--""’" ~~J

Cryptomeria japonica growing in a nursery in Maryland.mormamy pyramiaai namt mtn tne

type species’ cloudlike silhouette. It is the mostreliably cold-hardy cultivar and the best choicefor zone 6 gardens. A beauty as a specimen, innumbers it will also rapidly make a handsomescreen. ’Yoshino’ has been used to create a lush

background to the waterfall and mountain pathsof Tenshin-en, the Japanese garden at Boston’sMuseum of Fine Arts.

References

Bailey Hortorium. 1976. Hortus Third MacMillan Pub.Co. 341

Den Ouden, P, and B. K. Boom. 1965. Manual ofCultivated Conifers The Hague, MartinusNi~hoff, Netherlands.

Dirr, M.A. 1990. Manual of Woody Landscape Plants.Stipes Pub. Co.

Hornibrook, M. 1938. Dwarf and Slow-Growmg Comfers,2nd ed. Theophrastus, Noble.

Krussmann, G. 1985. Manual of Cultivated Comfers.Timber Press.

Van Gelderen, D.M., and I. R. P. van Hoey Smith. 1986.Conifers Timber Press.

Vidakovic,M. 1991 Com fers, Morphology and Vamation.Graficki Zavod Hrvatske, Zagreb.

Kim Tripp, a Putnam Fellow at the Arnold Arboretum,1994-1995, is now director of the New York BotanicalGarden.

Microbiota decussata: A Versatile Conifer

Nancy Rose

~ /~ icrobiota decussata is an elegant, low-

/ V / growing evergreen shrub that is finding-L 1 its way into more gardens every year.Its combmation of graceful form, attractive foli-age, cold hardiness, and landscape value earnedit a 1998 Cary Award, which annually honorsoutstanding woody plants for New Englandgardens. Microbiota decussata has gamed favorwell beyond New England, however, and gar-deners in many states may find it an excellentaddition to their landscapes.This unique conifer has a remote and limited

native range: the Sikhote Alin mountain rangein the southeastern leg of Siberia, bordering theSea of Japan. It is often found growing abovethe treeline, frequently in association withPinus pumila, a shrubby pine species, and inshrubland areas m the upper mountain valleysof the region. The species was first recorded bybotamst I. K. Shishkin in 1921, in the mountainsnortheast of Vladivostok, and named by botanistV. L. Komarov in 1923.

Despite being discovered and named over 80years ago, Microbiota decussata is often describedin garden catalogs as "new" or "recently discov-ered." This claim is actually not so far off, sincethere was a significant lag between the plant’sdiscovery and its introduction to gardeners inNorth America. The species was not mentionedin Hortus Third, the 1976 edition of the vener-able tome that lists cultivated plants of the U.S.and Canada. It has slowly become more availablein the nursery trade over the past 20 years, how-

ever, and is clearly now here to stay.Microbiota decussata is the lone species in its

genus, but it is not without relatives. It belongsto the cypress family, a wide-ranging group ofconiferous trees and shrubs that includes well-known evergreen genera like Jumperus, Thu~a(arborvitae), and Chamaecyparis (false cypress).Taxonomically, M. decussata is perhaps mostsimilar to Platycladus orientahs (oriental

arborvitae), but the two are different enough tomaintain their separate designations.With a height at maturity averaging only ten

to eighteen inches in most landscape plantings,the plant’s low, widespreading form resem-bles that of spreading junipers. (Interestingly,native Siberian specimens with heights rangingfrom eight inches to over three feet have beenreported, indicating that it may be possible toselect shorter or taller types from wild popu-lations.) Many long stems radiate horizontallyfrom the plant’s crown, creating a spread thatcan reach ten feet or more. As these mainstems grow outward, numerous gently archingsecondary branches rise from them, develop-ing first near the center of the plant. Since all ofMicrobiota decussata’s branch tips nod down-ward, the result is a wonderfully graceful, softlylayered appearance. The nodding branch tips arecharacteristic of the species and make it easy todifferentiate it from spreading jumpers, whosebranch tips tend to flare upwardThe individual branchlets of Microbiota

decussata are arranged in lacy, fernlike sprays,much like those of arborvitae; no doubt thisaccounts for another common name for theplant, "Russian arborvitae." The branchlets arecovered with closely pressed, scale-like needlesarranged in opposite pairs. The pairs emerge at90-degree angles from each other, resulting in aneatly layered, four-ranked arrangement termeddecussate-hence the plant’s specific epithetdecussata. The individual needles are tiny (one-eighth inch or less), with convex outer surfaces,a triangular shape, and tips that feel slightlysharp when you run a finger down the branchletbackwards, from tip to base.The foliage can safely be described as a pleas-

ant bright green during the growing season butdescribing its winter color is a highly subjec-tive exercise. Those who don’t like the plantuse terms like "dull brown" or "dirty purplish

16

Microbiota decussata has a natural affimty for rocks

brown" while those who find it appealingdescribe the color as anything from "magnificentcopper" to "rich bronze" or "burgundy purple." "

Beauty (and color descriptions) are clearly in theeye of the beholder. Plants grown where theyare shaded during the winter show less bronzingthan those in full sun. Some plants seem to greenup more quickly than others in the spring; per-haps in the future nursery growers should selectfor this trait in new cultivars.

Being a conifer, Microbiota decussata does ofcourse bear cones, but they are so small as to behardly noticeable. Male and female cones occuron the same plant-in other words, it is monoe-cious. The male cones are the smaller, aboutone-sixteenth to one-eighth inch long; theyrelease pollen in the spring. Female cones, aboutone-eighth inch long, consist of a single nakedseed held within two to four leathery scales; theseeds mature in late summer or early autumn.

It is a very cold hardy plant, surviving throughUSDA zone 3 (average annual minimum temper-ature minus 30 degrees to minus 40 degrees F). Infact, it seems to prefer cooler climates and mayfail to thrive in areas warmer than USDA zone6. Excellent soil drainage is a must, but as longas the site is well drained the plant can adaptto a range of soil types and pH levels. It growswell in evenly moist soil, but once establishedit also tolerates drier conditions. An inch or two

of organic mulch-wood chips,shredded bark, or pine needles-applied in a wide circle around theplant will help keep the root zonecool and moist. So far M. decus-sata has not shown susceptibilityto Phomopsis tip blight, a com-mon disease problem for some ofthe spreading junipers, and appearsto be free of other major disease orinsect problems.When Microbiota decussata

started to become available innurseries it was often touted as

extremely shade tolerant. Thiswas seen as a great advantage overspreading junipers, which growpoorly and exhibit thinning foliagein shade. More experience with

M. decussata has led to modified recommenda-

tions, however. It too is prone to limited growthand thinner foliage when grown m dense, fullshade, so the better choice seems to be partialshade or full sun exposure. In regions with hotsummers this Siberian native appears to benefitfrom partial shade, especially in the afternoon.Microbiota decussata is usually sold in con-

tainers at nurseries and garden centers, butis also available from a number of mail order

garden catalogs. While it can be grown fromseed, most commercial propagation is by rootedstem cuttings.This is a plant with multiple uses in the land-

scape. Because of its low height and wide spread,it makes an ideal evergreen groundcover, its ferny,layered foliage creating a three-dimensionaleffect that is lacking in many groundcovers. Ithas a natural affinity for rocks, whether sweep-ing around the base of a well-placed decorativeboulder or spilling over the top of a stone retam-ing wall. Attractive alone, it also combines wellwith small deciduous shrubs, herbaceous peren-nials, and other conifers. Even its bronze wintercolor shows to advantage when contrasted withthe dark green foliage of evergreens, the colorfulfruit of shrubs like Ilex verticillata ’Red Sprite’,or the light tones of ornamental grasses.

For a note about the author, see page 25.

Chionanthus retusus: The Chinese Fringetree °

Peter Del Tredici ~ jianhua Li

T Tandsome is a word often used to

describe the Chinese fringetree~. -L (Chionanthus retusus). Whenplanted in the open, this species devel-ops into an elegant small tree, twentyto thirty feet high with approximatelythe same spread. A century-old speci-men at the Arnold Arboretum is about

twenty feet tall by thirty feet wide, andwhen in bloom from late May throughmid June is totally covered with showy,white flowers. It is no exaggeration tosay that this tree is capable of puttingon one of the Arboretum’s best floral

displays. The blue-purple fruit, whichmatures from late September to Octo-ber, provides a second season of inter-est. Chinese fringetree is more tree-likeand graceful than its straggly Americancousin, C. vmginicus, and is not nearlyso late to leaf out in the spring.The species has a broad distribution m

Asia, where it shows considerable varia-tion in its growth habit. In cultivationat the Arnold, some specimens are mul-tistemmed, while others-especiallythose raised from Korean seed-are dis-

tinctly single-stemmed. The plant seemsto have broad ecological adaptability,growing equally well in the warm, dryclimate of southern California (USDAzone 9) and the cold, moist climates ofNew England (USDA zone 5). ( .When young, the Chinese fringetree’s bark

is a pale buff color, peeling off in papery strips.On mature trees, the bark is tight, with dis-tinct ridges and furrows. The lustrous leavesare elliptic to ovate in shape, three to eightinches long and one-and-one-half to four incheswide. The white flowers, each with four strap-like petals, are about an inch across and giveoff a delicate fragrance. They are produced at

An eighteen-year-old specimen of Chionanthus retusus growmg at theArnold Arboretum. Note the smgle-stemmed growth habit that hasdeveloped without prunmg.

the ends of the branches and completely hidethe foliage when the tree is in bloom. In NewEngland the fall color, being pale yellow, ishardly spectacular; in warm climates, thereis no fall color to speak of and green leavesstay on the tree through December. It is adapt-able in its environmental responses, beingtolerant of full sun to partial shade, moderatesummer drought, and a wide range of soil con-

18 s

The showy flowers and blue-purple fruit of Chionanthus retusus.

ditions. It is generally not bothered by insectpests or diseases.The Chinese fringetree belongs to the genus

Chionanthus, which was described by CarlLinnaeus m his Genera Plantarum ( 1737, 1754).The name was based on the American fringe-tree, which had been introduced to Europe before1736. Like the Chinese fringetree, Chionanthusvirginicus produces a profusion of showy, whiteflowers in spring, which explains Linnaeus’choice of name for the genus ( chion = snow;anthos = flower).The taxonomic history of the genus is also

interesting. In 1788, Swartz described a small,evergreen, Jamaican tree with small corolla lobes,naming it Thouinia to commemorate the Frenchgardener Andre Thouin (1747-1824). However,Linnaeus had already used this name in 1781.Accordingly, Swartz gave his new genus a dif-ferent name, Linociera, in honor of a sixteenth-century French physician, Geoffrey Linocier.Between 1791 to 1976 many species of Linocierawere described from both the old world and thenew. In 1976, William Stearn proposed the unionof Linociera and Chionanthus. The difficulty ofdistinguishing species of Loniciera and Chionan-thus had been recognized as long ago as 1860 byGeorge Thwaites, who suggested the two generabe merged but did not present a formal proposal.Thus, prior to 1976 botanists generally referreddeciduous species with big flowers (corolla 1.5

to 4 cm~ to Chionanthus and evergreen specieswith small flowers (corolla less than I cm) toLinociera. However, a small-flowered Ecuador-ian species (L. pubescens) is a deciduous treewhile a deciduous Florida species (C. pygmaeus)has small flowers. Other morphological traitsoverlap between Chionanthus and Linociera,and no clear-cut differences separate the two.

Therefore, Stearn’s proposal to unite them hasbeen widely accepted in the botanical commu-nity. The combined group is referred to as Chion-anthus because this name was published earlierthan Linociera. The union has led to the transferof numerous species from Linociera to Chion-anthus even though genetic studies have notbeen performed to determine the evolutionaryrelationships of deciduous and evergreen species.Modern DNA research will surely help clarifythe taxonomy of Chionanthus and Linociera.

References

Dirr, M. A. 1998. Manual of Woody Landscape Plants, 5thed. Stipes Publishing, Champaign, IL.

Gilman, E. F., and D. G. Watson. 1993. Chionanthusretusus, Chinese Frmgetree. Fact Sheet ST-160.Department of Environmental Horticulture,Flonda Cooperative Extension Service, Instituteof Food and Agricultural Sciences, Universityof Florida.

Peter Del Tredici is a senior research scientist and JianhuaLi is a taxonomist at the Arnold Arboretum.

Beach Plum: A Shrub for Low-Maintenance

Landscapes

Richard H. Uva and Thomas H. Whitlow

each plum (Prunus maritimaJ,B shrub native to the Atlanticcoast, is familiar to beachgoersfrom southern Maine through Mary-land, where populations can be foundon and near the coastal dunes. Sincecolonial times its fruits have been col-lected in the wild for preserves and

jelly and were reportedly used evenearlier by Native Americans. Nowa-days, although beach plum is occasion-ally found in the nursery trade, it israrely grown in cultivation. Demandis increasing for native species thatcan thrive in low-maintenance, poor-nutrient landscapes-reclamationsites, roadsides, sand dunes in need ofstabilization-and beach plum is an excellentcandidate to fill that need. By virtue of its showyspring flower display and colorful fruits, beachplum also warrants increased use in more inten-sively managed ornamental landscapes.Beach plums have extensive root systems, no

doubt an adaptation to a habitat that is character-ized by high wmds, blowing sand, unstable sub-strates, wind-borne salt, and soil that is low innutrients and water-holding capacity. It shouldbe noted that beach plum’s distribution is notlimited to sandy soils, however; it also thrivesunder cultivation on moist, rich soil as long asit has good drainage and full sun. Today, jellyproduction from wild-growing shrubs is a smallbut thriving cottage industry in the Northeast,and farmers are beginning to plant beach plumto make fruit more readily available.The horticultural literature of the 1940s

mentions several cultivars of beach plum thathad been selected for fruit production at thattime, but we have been unable to locate speci-mens. (If a reader knows of any still existing,

---------------------------

Prunus mantima.

we would appreciate hearing about it.) Morerecently, the Cape May (New Jersey) PlantMaterials Center of the Natural Resources Con-servation Service (NRCS) has released a selec-tion known as ’Ocean View’; it was developedfor stabilizmg coastal sand dunes, but couldbe used in any sunny, well-drained location.The information below has been adapted fromNRCS’ "Notice of Release of ’Ocean View’." 1/

A New Cultivar of Beach Plum

’Ocean View’ is a cross of four wild-growingstrains from Delaware, New Jersey, and Massa-chusetts that were selected for their exceptionalseedling vigor, foliage abundance, disease andinsect resistance, leaf retention, fruit produc-tion, and cold tolerance. It has been field-testedon sandy coastal sites from North Carolina toMaine and is recommended for use withinzones 5b to 8b.This new cultivar is an upright, densely

branched shrub with pale green foliage. Itsalternate, serrated leaves are elliptical to ovate

20

Beach plum on Cape Cod, Massachusetts.

in shape and range from about 1.5 to 2.5 inchesin length and half that in width. In early spring,before the leaf buds unfold, clusters of snowy-white blooms emerge to cover the crown of theshrub, creating a frothy splash in the otherwisegray landscape. The individual flowers, onlyabout one-quarter to three-quarters of an inchin diameter, take on a pink hue before droppingoff to be replaced by the emerging leaves. Theround fruits ripen to a bright red in late Augustor early September.’Ocean View’ seedlings should be planted at

a depth of approximately two inches above theroot collar on stable sand dunes and no deeperthan the root collar on inland soils. Fertiliza-tion helps with good establishment and vigorousplant growth. Recommended spacing of plantsvaries with intended use: to provide a dense bar-rier of protective vegetation, seedlings shouldbe placed about four to six feet apart, and whenused inland for residential areas or wildlife plots,about six to eight feet apart.

The availability of this new cultivar givesgardeners in the Northeast an opportunity toenjoy a bit of native beach vegetation in theirbackyards without adding to their list of mainte-nance tasks. And if you don’t care to use the fruityourself for jelly, wildlife will appreciate it.

References

James B. Newman and Cecil B. Currin. 1994. Noticeof release of ’Ocean View’ beach plum. U S.Department of Agriculture, Soil ConservationService, Technology Development andApphcation, Ecological Science, Washington,D.C. http://www.plant-materials.nrcs.usda.gov/njpmc/releases.html

For information on beach plum fruit crop developmentplease visit our website: www.beachplum.cornell.edu See also Arnoldia 62 4, "Tamingthe Wild Beach Plum" by R. H. Uva.

Dr. Uva and Professor Whitlow have collaborated on the

development of beach plum as a fruit crop for severalyears at Cornell University.

Calycanthus chinensis: The Chinese Sweetshrub

jianhua Li ~ Peter Del Tredici

alycanthus chinensis is a

~ beautiful deciduous shrubwith a narrow geographicdistribution m Zhejiang Province,China. It grows up to ten feet tallwith a broad profile. The leavesare oppositely arranged with shortpetioles and are glossy green witha touch of roughness on the uppersurface. In the Boston area its nod-

ding flowers appear in mid to latespring. Appearances notwithstand-ing, the sepals and petals are notdifferentiated (therefore termedtepals): the outer tepals are a silkywhite with a tinge of pink and adiameter of two to three inches,while the inner tepals are a waxypale yellow to white with maroonmarkings. Unlike the native Caly-canthus floridus the flowers arenot fragrant and are pollinated bysmall beetles.

Tepals and stamens occupy therim of a deep floral cup; the ovariesare attached to the side of the cup.The fruits, top-shaped with manyseeds, overwinter on the shrub. Inits natural habitat, it grows under-neath a canopy and therefore is bestcultivated in partial shade withwind protection and good soil mois-ture. In 1998 Michael Dirr describedit as "a unique plant but doubtfullyas worthy as Calycanthus floridus. "

Opinions may vary as to the species’comparative garden worthiness, butwhere evolutionary and taxonomic histories areconcerned, C. chinensis definitely provokes moreinterest. As a practical matter, the species is rarein the wild and needs our help to survive.

The pendant flowers of Calycanthus chinensis have an unusual, waxy texture.

Calycanthus chinensis belongs to Calycan-thaceae, which includes two genera and aboutten species.’ Chimonanthus (wintersweet) isthe other genus; it differs from Calycanthus in

22

In this closeup of a Calycanthus chinensis flower, the mnerand outer whorls of tepals are clearly msible.

The flowers of our natme eastern sweetshrub differ fromthose of their Chinese relatme both in form and fragrance.

many features, including morphology, woodanatomy, pollen, and embryology. Species ofChimonanthus are literally called "waxyprunus" in Chinese because it blooms in winterwith waxy yellow flowers that resemble cherries.C. chinensis was first described as a species ofCalycanthus2 and was later recognized as aseparate genus, Sinocalycanthus.3 Morphologi-cally, this species differs from other species ofCalycanthus in its white flowers and dimorphic(two forms), broadly ovate tepals. Therefore,many authors recognize this species as a separategenus from Calycanthus.4 However, we prefer totreat this plant as a species of Calycanthus forthe following reasons.

First, it is rare that species of different generahybridize successfully, but Calycanthus chinen-sis has been successfully crossed with C. flori-dus and C. occidentalis.s Second, differencesin DNA sequences are few among C. floridus,C. occidentalis, and C. chinensis.6 Third, thistreatment shows Calycanthus’ disjunct distri-bution in eastern Asia and North America. Anda final consideration-hardly a serious one-isthe tongue twisting required to pronounce thelong hybrid name Sinocalycanthus.When Calycanthus chinensis was first intro-

duced into cultivation in North America in theearly 1980s, its hardiness was unknown. Butexperience at the Arnold Arboretum has shownthe plant to be fully hardy in USDA zone 6, hav-

ing survived temperatures of minus 10 degreesF in 2003. The plants being offered for sale wereraised from seeds produced by plants growingoutdoors at the Arnold Arboretum since 1998.The parent plants were raised from seeds col-lected at the Nanjing Botanical Garden in 1994.

Endnotes ~

‘ Li, J. Ledger, T. Ward, and P. Del Tredici. 2004.Phylogenetics of Calycanthaceae based on molecularand morphological data, with a special referenceto divergent paralogues of the nrDNA ITS region.Harvard Papers m Botany 9: 69-83.

2 W. C. Cheng and S. Y. Chang. 1963. Scientia Srlvae 8: 1.3 - -

-. 1964. Genus novum calycanthaceaearumchmae onentahs Acta Phytotaxonomica Smica 9:135-138.

’ L Li 1989. Cytogeographical study of CalycanthusLmnaeus. Gmhaia 9: 311-316; Y. Li and P. T. Li.2000. Cladistic analysis of Calycanthaceae. journalof Tropical and Subtropical Botany 8: 275-281; M.Dirr. 1998. Manual of Woody Plants, 5th ed. Stipes,Champaign, IL.

5 F. T. Lasseigne, P. R. Fantz, and J. C. Raulston. 2001.~ Smocalycalycanthus raulstonn (Calycanthaceae/:A new mtergeneric hybrid between Sinocalycanthuschinensis and Calycanthus flondus HortScience36: 765-767; Todd Lasseigne, pers. comm.

‘ Li et al. 2004.7 G. H. Straley. 1991. Presenting Sinocalycanthus

chinensis. Arnoldza 51 / 1 18-22.

Jianhua Li rs a taxonomist and Peter Del Tredici is a semorresearch scientist at the Arnold Arboretum

Rhus trilobata: Worthy Plant Seeks Worthy Name

Nancy Rose

addled with common names like skunk-bush, stinking sumac, and ill-scentedsumac, Rhus trilobata is clearly a shrubin need of a good public relations agent. Thoseunflattering names refer to the strong scent itsfoliage and stems emit when crushed. Ignorethe unappealing monikers, and you will findthat its ornamental and environmental assetsare more than sufficient to make R. trilobata avaluable landscape plant.Rhus trilobata has a wide native range in west-

ern North America, reaching from the Canadian

province of Saskatchewan south to Texas andMexico but skipping the moist coastal areas ofthe Pacific Northwest. It grows in many ecologi-cal regions, from the Great Plains grasslands tomountain shrubland, chapparal, and forest areas,and is found in association with numerous spe-cies of deciduous and evergreen trees and shrubsas well as with grasses and forbs.Within its native range this deciduous shrub

can grow from two to twelve feet tall, withfour to six feet being typical in most land-scape settings; its height is determined in part

A lemonade-hke drmk can be made from the attractme red fruits.

24

by moisture availability. Its formranges from irregularly upright tomounded, with numerous slender,branched stems rising upward fromthe crown. These flexible youngstems have been used in basketryby Native Americans, accountingfor one of the plant’s lesser-knowncommon names: basketbush. Shootsalso emerge from the extensive sys-tem of woody rhizomes that spreadlaterally below ground, creatinga dense thicket that in width can

equal two or more times the plant’sheight. A taproot together with alarge mass of more shallow fibrousroots anchor the shrub.The leaves of Rhus trilobata,

compound and alternately arrangedon the branches, consist of threesubsessile (nearly stalkless) leafletsthat are generally ovate or rhom-boidal in shape. The terminal leaf-let is the largest, with a length ofone to two-and-one-half inches; it isoften distinctly three-lobed (hencethe specific epithet trilobata) butat times displays only shallow ornegligible lobing. Its leaf marginsare coarsely toothed, most teethbeing rounded although some areslightly pointed. Leaf surfaces,while variably pubescent on youngleaves, usually become smoothand slightly glossy as the foliagematures. Medium to dark green in summer,the leaves often develop excellent fall foliagecolor that ranges from yellow to orange, red, andreddish purple.

In spring Rhus trilobata blooms before itsfoliage appears, the flowers emerging fromshort, catkin-like spikes borne at the branchtips. Individual flowers may be unisexual orbisexual, with both types occurring on mostplants. Only about one-eighth inch long, theyare light yellow or greenish yellow and have fivepetals. The fruit is a red, subglobose (not per-fectly round) drupe about one-quarter inch long,slightly hairy and a bit sticky on the surface andcontaining a single dark brown nutlet. Mature

New leaves are downy, usually becommg smooth and glossy mth matumty.In fall the green gives way to yellows, orange, reds, and reddish purple.

fruits have a tart taste; a tangy lemonade-likedrink can be made by steeping them in water.The fruits, leaves, stems, and roots of R. tri-lobata have been used for various culinary,medicinal, and other utilitarian purposes bynative cultures in the western United States.

Six naturally occurring varieties of Rhustrilobata are recognized: var. anisophylla, var.pilosissima, var. quinata, var. racemulosa, var.simplicifolia, and var. trilobata. R. trilobatavar. trilobata-so named to indicate that it dis-

plays the species’ typical morphology-coversthe entire native range. The other varieties varyin such features as height, growth habit, leafsize and form, and fruit pubescence. Where the

25

ranges of these varieties overlap, plants often showmtermediate morphological characteristics.Rhus trilobata looks very much like its more

widely available cousin, R. aromatica. Theresemblance is close enough that skunkbushwas previously listed in taxonomic references asa variety (R. aromatica var. trilobata) rather thanas a separate species. Morphological differencesbetween the two are few. R. trilobata’s leaves,flowers, and fruits are generally smaller andits terminal leaflets more distinctly lobed thanthose of R. aromatica, but these features show

enough variability to make them unreliable asdiagnostic tools. It is in geographic distributionthat the two species show clear differences, withR. trilobata occupying a western range whileR. aromatica is found east of the Great Plains.A corresponding difference is found in theirenvironmental adaptations: R. trilobata toler-ates fairly dry, alkaline soils while R. aromaticaprefers moist, slightly acidic sites. The leaves ofboth species emit a distinct odor when crushed,but the somewhat less pungent scent of R. aro-matica earned it the common name "fragrantsumac" while R. trilobata is stuck with its less-

than-flattering nicknames.As its wide natural range might indicate, Rhus

trilobata is an adaptable plant. It grows well insomewhat alkaline soils but also appears to tol-erate neutral to slightly acidic soils. Most refer-ences list it as winter hardy to USDA zone 4(average annual minimum temperature minus20 to minus 30 degrees F), but the hardiness ofindividual plants is likely to vary dependingon seed provenance. It thrives in either full sunor partial shade, but fall foliage color is usuallybetter in full sun.

Because it is well adapted to drier climaticconditions, Rhus trilobata is an excellent choicefor xeriscaping. Annual precipitation in most ofits range averages just 10 to 20 inches; by con-trast, the average is 42.5 inches in Boston and29.4 inches in Minneapolis-St. Paul. In USDAregional evaluations, a seed-grown selection ofR. trilobata from Bighorn County, Wyoming,fared best at evaluation sites with drier climaticconditions. Specimens failed to thrive and/orshowed higher incidence of fungal leaf spots insites with poorly drained soils, higher rainfall,and higher humidity.

Rhus trilobata can be propagated in severalways. One of the simplest is by root (rhizome)cuttings. In spring, sections of rhizome can bedug up, cut into sections, and potted or plantedin a propagation bed. Alternatively, softwoodstem cuttings taken in early to mid summer canbe rooted in a peat-perlite medium under mist.For seed propagation, the fleshy pulp should firstbe removed from the seeds of ripe fruits. Theseeds (nutlets) have a very hard coat that mustbe cracked by mechanical or chemical scarifica-tion, after which they can be planted directlyin a seedbed. Plants of R. trilobata can most

easily be found in nurseries in western states,but several mail-order garden catalogs offercontainer-grown plants for sale.

This sumac can be used effectively in severalways. Its dense network of roots and rhizomesmakes it an ideal plant for holding soil on steepslopes, banks, and terraces. It also works wellin large-scale mass plantings since its suckeringhabit allows it to fill an area quickly. Its abilityto tolerate drought and grow in rocky or grav-elly soil makes it a good choice for dry, difficultsites. New England gardeners should not be putoff by Rhus trilobata’s affinity for arid soils,however. As long as it is planted on a sunny,well-drained site where flooding is not a prob-lem, it will do well in those hilly or rocky areasthat are common in the Northeast but less thanideal for more common garden shrubs. Onceestablished, R. trilobata requires little mainte-nance ; pruning to control height and improveappearance can be done as needed. With itsattractive spring flowers, colorful fruit, andbright fall color, R. trilobata is a worthy additionto native plant displays, naturalized gardens,commercial properties, and other sites in needof a tough, adaptable shrub.

Nancy Rose is a horticulturist and educator with theUniversity of Minnesota Extension Service. She hasbeen growing and evaluating woody ornamental plantsfor many years, most recently at the University ofMinnesota Landscape Arboretum and previously at theMorton Arboretum near Chicago. She is also a gardenwriter and photographer, writing a gardening column forthe Mmneapol1s Star-Tmbune and wriring and editmgfor several gardemng magazines. Nancy is co-author ofthe books Shrubs and Small Trees for Cold Chmatesand The Right Tree Handbook.

Demystifying DaphnesBob Hyland

have been a fan of shrubby daphnes for a long

time despite their reputation as persnicketyand unpredictable garden plants. I love todrink in their heady fragrance when they arein bloom. My first encounter with the genuswas with Daphne odora (winter daphne)-to beexact, a handsome cultivar called ’Aureomar-

ginata’. It’s a deliciously sweet-smelling shrub,very reminiscent to me of jasmine. Its leatheryleaves are evergreen, a deep, shiny green edgedwith yellow. The almost white flowers are anattractive reddish purple on the outside.Daphne odora is hardy to USDA zones 7 to 9.

With careful siting, a little extra winter protec-tion, and some tender loving care, I was able tocoax it into overwintering in my garden in Wilm-ington, Delaware. Later, in my San Franciscogarden, the generally frost-free, Mediterraneanclimate made the ~ob much easier; m fact, someof my snobbier gardening friends considered it abit pedestrian.Daphne serves as both the common name and

genus epithet of some fifty species of decidu-ous, semi-evergreen, or evergreen shrubs nativeto Eurasia (Europe, N.Africa, and temperateand subtropical Asia). The genus is a memberof Thymelaeaceae (mezereum family), whichincludes about forty genera of deciduous andevergreen trees and shrubs native to temperateand tropical regions of both hemispheres. Otherlesser-known cultivated ornamental plants inthis family include Dirca and Edgeworthia.The plant’s name may have come from the

nymph of classical Greek mythology. As thestory is told, Daphne was loved and relent-lessly pursued by Apollo, the god of prophecy,music, medicine, and poetry, whose advancesshe tried to thwart. After praying for help toGaia, goddess of the earth, she was changedinto a laurel tree and evaded her pursuer. It ismore likely, however, that the name comesfrom an Indo-European word meaning "odor." "

The root and bark of Daphne are said to havebeen used for toothaches, skin diseases, and

even cancer, which seems odd since all parts ofthe plant are poisonous.

In the Northeast several Daphne species arehardy and have long been cultivated for theirhandsome foliage and intoxicating fragrance.Daphne flowers are tubular and flare at themouth into four spreading lobes. They appearon small to mid-sized shrubs that make superbgarden plants. Their dense, broad, moundedform is particularly well suited to small, inti-mate gardens where they can be viewed closeup,but daphnes have a place in any landscape. Theycombine nicely with many perennials that toler-ate sun or partial shade. Good bedfellows includelow-growing thymes and sedums, variegatedhakone grass (Hakonocloa macra ’Aureola’/,sedges jCarexj, hostas, coral bells (Heuchera),and hardy geraniums. Most of their allegedunpredictability can be overcome with care-ful placement in the garden and good culture.I heartily agree with Michael Dirr and otherdaphne-philes-a single flowering season wouldjustify their use.

Growing DaphnesDaphnes are widely thought to be unpredict-able and subject to dying for no apparent rea-son : many a gardening friend has told me not toget too attached to one. It is true that daphnesdislike extremes of moisture or temperature.Their root systems are picky, preferring not tosit in water or to dry out. Moist but well-drained,humus-rich soil is ideal, and mulching helpskeep roots cool in summer. Some English gardenbooks suggest that daphnes do best in limestonesoils, but this has not been my own experience.I recommend acidic to slightly alkaline soils. Atthe Arnold Arboretum, several Daphne speciesgrow well in acid soils of pH 4.5 to 5.

Generally speaking, you can plant daphnesin full sun to partial shade, but the foliage, par-ticularly on the variegated leaves, does not liketo bake in hot summer sun-afternoon shade isideal. Daphnes also do not take kindly to trans-

27

The variegated leaves of Daphne x burkwoodii ’Carol Mackie’. ’.

planting once established m the garden; it is bestto plant container-grown stock in a permanentlocation. Keep pruning to a minimum, with judi-cious deadheading and light tip pruning. Do nottry to rejuvenate plants by cutting back hard-this can easily sound the death knell.

Besides this basic knowledge, all that’s neededfor successful daphne culture is planning aheadand some extra tender loving care. Find just theright spot, take the time to prepare and amendthe soil, monitor moisture levels, provide a win-ter mulch over the roots, and daphnes will gener-ally flourish and bloom for many years.The Arnold Arboretum will offer the follow-

ing three dazzling daphnes at their fall 2005plant sale.

Daphne x burkwoodii ’Carol Mackie’This is one of the most striking of all daphnes-for that matter, of all variegated shrubs. A geneticmutation, or sport, of hybrid Daphne x burk-woodii (D. cneorum x D. caucaslca/, this cul-tivar was discovered and originally propagatedby Carol Mackie in her Far Hills, New Jersey,garden in 1962. Carol Mackie was a passionate

gardener and a very active member and officer ofthe Garden Club of Short Hills and the GardenClub of America. She developed a deep mterestin unusual plants and a very keen eye for the rareand unusual.Her namesake cultivar is highly prized for

its small, intensely green leaves that are hand-somely edged in a creamy white to golden yel-low. In May and June in New England, the foliageis enhanced by rose-pink buds that unfold tostar-shaped, richly fragrant, pale pink flowersborne in dense, terminal umbels, two inches indiameter. Individual flowers are about a half-mch in diameter and are followed by small, red,drupehke fruits.

’Carol Mackie’ matures into a dense, moundedshrub that ultimately reaches three to four feetm height and width. It exhibits a tough constitu-tion and is hardy to USDA zones 4 to 8; it wasonce listed as a "Top Ten" ornamental plantin Vermont. Accordmg to Michael Dirr m thefifth edition of his Manual of Woody LandscapePlants, Daphne x burkwoodii ’Carol Mackie’survived minus 30 degrees F without injury inthe Umversity of Maine’s display gardens. In

28

more southerly parts of its hardiness range, theplant remains evergreen through winter.Tom Ward, co-director of living collections at

the Arboretum, holds D. x burkwoodii ’CarolMackie’ in high esteem. He reports that it hasperformed well both at the Arboretum and inhis own New England garden. If you’ve had thesame success with’Carol Mackie’, you might trya newer cultivar, ’Briggs Moonlight’. Introducedby Briggs Nursery, Elma, Washington, it offersthe reverse leaf variegation of ’Carol Mackie’,with creamy yellow centers and narrow, darkgreen margins.

Daphne genkwa (Lilac Daphne)Daphne genkwa hails from China; it was intro-duced into cultivation in the United States in1843. An open, deciduous shrub with erect, slen-

der, sparsely branched stems, it is a gem in thespring garden. Axillary clusters of two to sevenlovely, one-fourth-to-three-fourths-inch diam-eter, lilac-colored flowers bloom during Mayon naked stems of the previous year’s growth,just before and while new foliage is beginning toemerge. Floral fragrance is very subtle to nonex-istent. Dry, ovoid fruits develop after flowering;

Daphne genkwa.

they are grayish whiteand nothing to writehome about.

Mid-green, one- tothree-inch-long leaves,lance-shaped to ovate,are arranged oppositely(occasionally alternate-ly) on stems. This isunusual among daphnespecies, which nor-mally sport alternatelyarranged leaves. Leavesare softly silky whenfirst unfurling.Daphne genkwa is

hardy to USDA zones5 to 7 and generally

. I’ . 11. 11 , ...

matures to three to four feet in height andwidth. Currently no specimens of D. genkwa areplanted out in the Arboretum’s living collec-tions, but one-descendant of wild-collectedplants from the former Czech Republic -isgrowing in the nursery. The Arboretum’s plant

Daphne x transatlantica ’Summer Ice’. ’.

records also indicate that wild-collected seed ofD. genkwa from China was received from E. H.Wilson in 1907.

Daphne x transatlantica ‘Summer Ice’

Daphne x transatlantica is a newly found hybrid,the result of a naturally occurring cross betweenD. collina and D. caucasica (caucasian daphne).it combines the small stature and strong fra-grance of D. collina with the fragrance and longblooming period of D. caucasica. D. x transat-lantica is a compact, semi-evergreen, moundedshrub that blooms continuously in New Englandfrom May to frost with small, delightfully fra-grant, white flowers. The late Jim Cross, founderof Environmentals Nursery in Cutchogue, LongIsland, is responsible for introducing this hybridinto the nursery trade. He originally sold it asa form of D. caucasica, but molecular studieslater proved it to be a hybrid that has been namedD. x transatlantica.The cultivar ’Summer Ice’ grows into a well-

behaved, domed shrub that reaches three to fourfeet in height and width. The delicately varie-gated leaves sport fine, creamy white edges-similar to but more demure than D. burkwoodii’Carol Mackie’. Its spicy white flowers are borneabundantly at the ends of branches in late spring,followed by sporadic summer bloom and a strongfall show. ’Summer Ice’ is hardy to zone 5.

Bob Hyland is co-owner and manager of Loomis CreekNursery, Hudson, New York, pubhc garden consultant,and former vice president of horticulture and operationsat Brooklyn Botanic Garden. He frequently writes aboutplants when not watering.

Index to Volume 63Numbers m parentheses refer to issues, those m boldface to illustrations of the entnes.

"A Good Day Plant-Collecting inTaiwan," Rob Nicholson 1. 20-27

Abies nephrolepis 3: 26Abies nordmanmana 4. 8Abraham J. Miller-Rushing, "Herbar-ium Specimens as a Novel Tool forClimate Change Research," withDamel Pnmack et al.

Acer alleghamensis 4: inside frontcover

- negundo 1: 28- pensylvamcum 1: 28-platanoides 1~ 28- ru brum 1: 29Aceraceae 1: 28

Adelges tsugae (HWA) 2: 33Aesculus 1: 3, 4-hippocastanum 1: 3, 4, 5- hippocastanum cv. ’Baumanml’ 1: 3-pama 1: 3, 4, 5-x x carnea 1~ 3, 4, 5, 6"Agamst All Odds: Growing Franklm-

ia in Boston" 4: 2-7Alisan National Scemc area [Taiwan]

1: 23

Alpinia speciosa 1: 24Amentotaxus Preserve [Taiwan] 1: 24Amentotaxus formosana 1: 22-25Ames, Oakes 4: 10Andersen, Phyllis, "Ilex pedunculosaThe Longstalk Holly" 4: 11-12

Anemone ’Groene Ridder’ 1: insidefront cover

amse, false 1: 10

arbormtae, oriental 3: 41, inside backcover

- Russian 4: 15Arnold Arboretum 1: 32, 2: 16, 26,27-- Bussey Hill 4: 2, 6, 9- - Center for Tropical Forest Sci-

ence 3: 7-- Chinese Path 4: 2, 6, 9-- collection of eastern Asian pho-

tographs 3’ 34-- Dana Greenhouses 2: 3; 3: 22-- Fall Plant Distribution and Sale,

1980-2005 4: 8-- Hemlock Hill 2: 35-36, 37, 38-- Leventritt Garden 1: 8--Phellodendron amurensis col-

lection 1: front and back covers- - Weather Station Data-2003

63:2

Astragalus 3: 14

Bartram, John 3: 29; 4: 3, 7Bartram, William 4: 3, 4, 5, 7Bartram’s Garden 4: 4, 5"Beach Plum: A Shrub for Low-Main-tenance Landscapes," Richard HUva & Thomas H. Whitlow 4:19-20

beach plum 4. 19, 20beautybush 4’ 8Betula ermannn 3: 26- platyphylla 3 : 25Bhthdale Romance [Nathaniel Haw-

thorne] 3 : 28, 30Book of Fruit 3: 28box elder 1: 28Brook Farm, West Roxbury, MA 3:29,30

Browne, D J. 4: 4 ,

buckeye 1: 3, 5- red 1: 3, 4, 5Bull, Ephraim Wales 2: 14, 15, 17 7

Caesalpmioideae 3: 6"Calycanthus chinensis The ChmeseSweetshrub," Jianhua Li & PeterDel Tredici 4: 21-22

Calycanthus chinensis 4: 21, 22- flondus 1 : 4; 4: 21, 22Calhcarpa dichotoma ’Issai’ 4: insideback cover

camphor tree 3: 4, 36"Capturing and Cultivating Chose-

nia," Peter Del Tredici 3: 18-27Carr, Robert 4: 5Carya ovata 3: 9Caryophyllus florepleno 1 : 1

cedar, Japanese 4: 13, 14Cephalotaxus mlsomana 1: 22-24Cercis canadensis 1: 8

Chamaecypans 1 : G, 10- pisi f era 1: 6, 7- cvs. 1. 6, 7Changbai Shan 3- 13, 16 18-19 20 2125-27

Chatsworth Bakewell, Derbyshire 2:inside front and back covers

Chaw, Shu-Mlaw 1: 22-24, 25, 26Chen, Chih-Hui 1: 24-26chestnut 3: 3Chimonanthus 4: 21, 22China 3: 9, 10, 16,34,38,43"Chionanthus retusus. The Chmese

Fnngetree," Peter Del Tredici &

Jianhua LiChionanthus retusus 4: 17, 18

- vmgmicus 4: 17, 18 8"Chosenia: An Amazing Tree ofNortheast Asia," Inna Kadis 3.8-17 7

chosema 3: 8-9, 11, 12, 14, 15, 16, 23, 24Chosema 3: 21, 22, 23, 24-arbutifoha 8, 9, 10 13Cmnamomom camphora 3: 36- sp. 2: front cover

Concord, MA 2: 14Connor, Sheila, "The Nature of

East Asia: Botanical and Cultural

Images from the Arnold ArboretumArchmes" 3: 34-44

Corlett, Richard, "Dipterocarps: TreesThat Dominate the Asian Ram For-est" with Richard Pnmack 3: 2-7

Cornales 1: 9

cornel, Japanese 1: 9cornelian cherry, European 1: 9Cornus altermfoha 1: 9- flonda 1: 9- kousa 1: 9-mas 1 : 9-nuttallm 1: 9- officmalls 1 : 9

crabapples 1: 8cranberry 2: 19, 20cryptomena, Japanese 1: 8Cryptomena japonica 1: 8; 4: 13, 14--’Yoshmo’ 4. 14

Cycads 1: 25Cycas taitungensis 1: 25, 26, 27cypress, Leyland 4: 14 4- sawara false 1: 6, 7

dammar [resm] 3: 4daphne, lilac 4: 28- winter 4: 26

Daphne x burkwoodm ’Carol Mackie’4: 27

- genkwa 4. 28- odora 4: 26- x transatlantica ’Summer Ice’ 4:

28Damdia mvolucrata 3: 37; 4: 8, 10- - var. mlmonmana 4: 8, 10De Hart, William 4: 4Del Tredici, Peter 3: 26; photos by 2:

front cover; 4: front cover- - - "Agamst All Odds: GrowmgFrankhnia m Boston" 4: 2-7--- "Calycanthus chinensis: TheChinese Sweetshrub," with JianhuaLi 4: 21-22

30

- - - "Capturing and CultivatingChosema" 3: 18-27--- "Chionanthus retusus: TheChinese Fnngetree," with JianhuaLi 4: 17-18

- - - "Finding a Replacement forEastern Hemlock: Research at theArnold Arboretum," with AliceKitayma 2: 33-39

- - - "Herbarium Specimens asa Novel Tool for Climate ChangeResearch," with Abraham J. Miller-Rushmg et al. 2: 26-32

"Demystifying Daphnes," Bob Hyland4: 26-29

Diospyros 3: 4- kaki 3: 38, 39Diploblechnum frasem 1 : 24

Dipterocarp 3: 2-6, 7Dipterocarpaceae 3: 3"Dipterocarps: Trees That Dominatethe Asian Ram Forest, " RichardCorlett and Richard Primack 3:2-7

Dipterocarpus 3: 3- costulatus 3: back cover

Dirr, Michael 4: 21, 26, 27-28disjunct species, East Asian-easternNorth America 1: 10

dogwood, alternate-leaved 1: 9- East Asian giant 1: 9- flowering 1: 8- kousa 1: 9- western flowering 1: 9"Dove Tree: A Long Journey West, "

Richard Schulhof 4: 9-10 0dove tree 4: 9, 10Dryobalanops aromatica 3 : 4

East Tennessee State University 1: 2,7,8 8

El Niiio-Southern Oscillation events

3: 5, 6elm, American 2: 9, 11, 12, 13, 16-17 7- Enghsh 2: 11 1"Elms at Yale College," engraving byW. H. Bartlett 2: 8-9

Ericaceae 2: 18 8

Evelyn, John 1: 14, 16-17, 19

Famchild, David 2: 3, 17 7Farges, Paul Guillaume 4: 9, 10Farrar, Reginald 3: 41 1Faxon, C. E., illustration by 4: 5Fernald, M. L. 1: 29"Finding a Replacement for EasternHemlock: Research at the Arnold

Arboretum," Peter Del Tredici andAlice Kitajima 2: 33-39

Flora of the Lesser Antilles 2 : 6

Formosa, see TaiwanFrankhma alatamaha 4: 2-6, 7fringetree, Chmese 4: 18

genetic variation, mutational 1: 2Gondwana 3: 3

Gore, Christopher 2: 10grape, Concord 2: 9, 15, 16, back

cover

- European wme 2: 14 4- fox 2: 14 4

Greeley, Horace 2: 15gum, East Asian 1: 9- eastern American black 1: 9

Hamamehs x intermedia 1 : 4- japonica 1 : 4- molhs 1: 4

Hamilton, William 2: 10 0Hammond Woods, Newton, MA 1:

28, 29Harvard University 1: 29- - Herbaria 2: 3

Hawthorne, Nathaniel 3: 28-30, 31,32-33

Heather 2: 22

Hedysarum 3: 14hemlock woolly adegid 2: 33hemlock, Carolina 2: 33- Chinese 2: 33, 34-36, 39- eastern or Canadian 2: 33, 35, 36- mountain 2: 33- northern Japanese 2: 33, 34- southern Japanese 2’ 34- western 2: 33

Henry, Augustine 4: 9, 10"Herbarium Specimens as a NovelTool for Climate Change Research," "

Abraham J. Miller-Rushing, DamelPnmack, Richard B. Pnmack, Caro-line Imbres, and Peter Del Tredici2: 26-32

herbarium specimens 2: 26-32Hers, Joseph 3: 35, photos by 3: 41hickory, shagbark 3: 9Hippocastanaceae 1: 5Historic Bartram’s Garden 4: 3

holly, American 4: 12 2- European 4: 12 2- evergreen American 1: 8- - European 1: 8Hopea 3: 4- ponga 3 : 5horse chestnut 1: 3, 4, 5--red 1:3 3"Horticulture and the Development

of American Identity, " Philip J.Pauly 2: 8-17 7

House of Seven Gables [NathanielHawthorne] 3: 32

Hovey, Charles 2: 15Howard, Richard Alden 2: 2-7HWA (Adelges tsugae~ 2: 33-36Hwang, Shy-Yuan 1: 26hybridization 1: 3-6Hyland, Bob, "Demystifying Daph-nes" 4: 26-29

Ilex aqmfolmm 1 : 8; 4: 12 2- opaca 1: 8; 4: 12- pedunculosa 4: 12, back cover"Ilex pedunculosa. The LongstalkHolly," Phyllis Andersen 4: 11-12 2

illipe nuts 3: 6Imbres, Caroline, "Herbarium Speci-mens as a Novel Tool for Chmate

Change Research," with Abraham J.Miller-Rushing et al. 2: 26-32

"In Favor of Trees," John BnnckerhoffJackson 1: 13-19

"In Memonam : Richard Alden How-ard, 1917-2003," Judith A Warne-ment and Carroll E. Wood, Jr. 2:2-7

"In the Library: Hortus Nitidissimis, "

Sheila Connor 1: 32Indonesia 3: 3International Umon for Conservation

of Nature and Natural ResourcesRed List of Threatened Plants 1: 21 1

Ishikawa, Shmgo 3: 22

Jack, John George 3: 34, 35-36; 4: 6, 7;photos by 3: 36 6

Jackson, John Brinckerhoff, "In Favorof Trees (1994)" 1: 13-19, drawmgsby 1: 15, 16

Japan 3: 9, 22, 35Jefferson, Thomas 2: 10Johnson, Ethan W., photo by 4: back

cover

Juniperus squamata var. meyen 3: 41

Kadis, Irma 3: 21, 22- - "Chosema: An Amazing Tree of

Northeast Asia" 3: 8-17 7Kalmia latifoha ’Comet’ 4: insideback cover

2014 2014 ’Raspberry Glow’ 4: 8kapur tree 3: 4Kitajima, Ahce, "Finding a Replace-ment for Eastern Hemlock:Research at the Arnold Arboretum," "

with Peter Del Tredici 2: 33-39Kolkmtzla amabihs ’Pink Cloud’ 4: 8Korea 3: 9, 18, 20, 35

Lan Lee 3: 42Larix olgensis 3 : 27Lenox, MA 3: 32

31

Levy, Foster, "Using Arboreta toTeach Biological Concepts" 1: 2-12with Tim McDowell

Li, Jianhua, "Calycanthus chinensisThe Chinese Sweetshrub, " mthPeter Del Tredici 4. 21-22-- "Chionanthus retusus. The Chi-nese Fnngetree," with Peter DelTredici 4~ 17-18

Lilmm regale 3: 37lrly, Easter 3: 37lime tree 1. 17linden 17

"Lmgonberry: Dainty Looks, SturdyDisposition, and Tasty Berries," LeeReich 2’ 18-25

lingonberry 2 18, 19, 20, 21, 22, 23,24-25

Lmociera 4’ 18Lmodendron chmense 1. 12

- tuhpifera 1: 8, 12-- x chmense 1: 12

locust, black 1: 4- bristly 1: 4- casque rouge 1: 4

longstalk holly 4: 11, 12, back coverLyon, John 4: 3

Madsen, Karen, photo by 1 ~ front andback covers

magnolia, lrly-flowered 1: 3, 4- saucer 1: 4- Yulan 1. 3, 4Magnolia denudata 1: 2, 3, 4- hlnflora 1: 2, 3, 4- x soulangiana 1: 3---’Alexandrma’ 1: 2, 3, 4- stellata ’Centennial’ 4: 8

- vmgmana ’Moonglow’ 4: insidefront cover

Malay Peninsula 3: 3Malaysia 3: 3Manmng, Robert 3. 28maple, Norway 1: 28- red 1 ~ 8, 29, 30, 31- striped 1. 28Marble Faun [Nathaniel Hawthorne]

3: 33

Marshall, Humphry 4: 3McDowell, Marta, "Verdant Letters:Hawthorne and Horticulture" 3:28-33

McDowell, Tim, "Usmg Arboreta toTeach Biological Concepts" 1: 2-12with Foster Levy

Meehan, Joseph 4: 4Meehan, Thomas 4: 4, 5, 6, 7Meyer, Frank Nicholas 3: 34, 38-39;photos by 3: 38, 39

Meyer, Paul 1: 22

mezereum family 4: 26"Microbiota decussata A Versatile

Conifer," Nancy Rose 4’ 15-17Microbiota decussata 4: 15-16

Nhquel, Fnednch Anton Wilhelm 4: 11Mongohan athletes 3 40morphological variarion 1: 6-8Mosses from an Old Manse [Nathan-

iel Hawthorne] 3: 30mountain laurel 4. 8Mussaenda pubescens 1~ 24

Nakal, Takenoshm 3: 10Nanjing Botanical Garden 3. 19; 4: 22Natural History Museum, London

1: 32Nature of East Asia: Botanical andCultural Images from the ArnoldArboretum Archrves," Sheila Con-nor 3: 34-44

Nicholson, Rob, "A Good Day: Plant-Collectmg m Taiwan" 1 ~ 20-27, 25

North American-Chinese Plant Ex-

ploration Consortium (NACPEC)3: 18, 20

Nyssa smensls 1: 9- sylvatica 1. 9

oak 3: 3-4, 6Old Manse, Concord [MA] 3. 30Our Old House [Nathaniel Haw-

thorne] 3 : 33Oxytropis 3: 14

Panax gmseng 3: 20

parent-hybnd combinations 1: 4Pauley, Philip J., "Horticulture andthe Development of AmericanIdentity" 2: 8-17

Peabody,Sophia 3’29 30pear tree 2: 27

Perry, Lily M. 2: 2persimmon sugar 3: 38

Philippines 3’ 3Phomopsis 4: 16Phyllosticta aurea 4: 13phylogenetic biogeography 1: 2, 8-10Phytophthora cmnamom 4: 7Pierce, Franklin 3: 32Pmus x acenfoha 1: 4- koraiensis 3: 25- pumila 4: 15- sylvestmformis 3: 25- occidentahs 1: 4- onentalls 1: 4

Platycladus omentahs 3: 41, insideback cover

plum yew, Wilson’s 1. 22, 23Polygonatum alte-lobata 1: 23poplar 3: 9, 13

- Lombardy 2: 10Poncirus tnfol1ata 4’ inside back

cover

Populus 3: 21Primack, Damel, "Herbarium Speci-mens as a Novel Tool for Chmate

Change Research," with Abraham J.Miller-Rushing et al. 2: 26-32

Pnmack, Richard, "Dipterocarps:Trees That Dominate the AsianRam Forest" with Richard Corlett3.2-7

- - "Herbamum Specimens as aNovel Tool for Climate ChangeResearch," with Abraham J. Miller-Rushing et al. 2: 26-32

- - "The Sex Life of the Red Maple"1: 28-31

Prince family nursery 2: 10, 14Pnnceton Nurseries 2: 16Prunus mantima 4: 19-- ‘Ocean View’ 4: 19

Pseudodrynana coronans 1: 26Purdom, William 3: 34, 35, 39-41;photos by 3: 40

Pusey, Nathan 2: 3Pyrus 2: 27

Rafinesque, Constantine 4: 4rain forest, Amazoman 1. 14-- Asian 3: 4redbud 1: 8redfire 4: 13Rehder, Alfred 3: 35Reich, Lee "Lingonberry DaintyLooks, Sturdy Disposition, andTasty Berries" 2: 18-23, 24, 25

Rhododendron dauncum 1: 11-mmus 1: 11

-’P.J.M.’ 1: 11- vasey 2: 28Rhus aromatica 4’ 25"Rhus trilobata- Worthy Plant SeeksWorthy Name," Nancy Rose 4:23-26

Rhus trilobata 4: 23-24, 25Robmia hispida 1: 4- pseudoacacia 1: 4- x margaretta 1: 4

Rock, Joseph 3: 34, 35; photos by 3’42~13

Rosa ’L’admirable’ 1 ~ inside backcover

Rose, Nancy, "Microbiota decussata~A Versatile Comfer" 4: 15-17

- - "Rhus tmlobata: Worthy PlantSeeks Worthy Name" 4: 23-26

Royal Botamc Gardens, Kew 1: 32; 3:37,39

Rutgers Umversity 2: 16

32 l

"Salem Common on Training Day,"painting by George Ropes, Jr. 2: 10

Salem, MA 3: 28, 32Salicaceae 3: 10, 13, 21Sahx 3: 21- tnandra 3: 9

Sargent, C. S. 1: 32; 3: 32, 27, 28, 41,42 ; 4 : 5, 6, 7, 9, 10, 11, 12

Scarlet Letter [Nathaniel Hawthorne]3: 30-31

scholar tree, Chinese 3: 36

Schulhof, Richard, "The Dove Tree: ALong journey West" 4: 9-10

"Sex Life of the Red Maple," RichardPnmack 1: 28-31

Shanghai Plant Physiology Institute2: 2

Shenyang Institute of Applied Ecol-ogy 3: 19

Shorea 3: 3Siberia 3: 8, 9, 10"Silver Anniversary: The Fall PlantDistribution and Sale, 1980-2005"4: 8

Sm No 3: 42

Singapore Botanical Garden 3: 38Sinocalycanthus 4: 22- cAjnensn 1. 4sister species, mcanant 1: 10Skinner, Francis 1: 32Skinner, Jr., Francis 1: 32species concepts 1: 2

spruce, Mornson’s 1: 23Stewartia ovata forma grandiflora 4:

front cover

Styphnolobmm ~apomcum 3: 36Sun Long Xing 3: 21, 22Sutton, Stephanne B. 4: 9sycamore, eastern 1: 4- London 1: 4- oriental 1:4

Sylva [John Evelyn] 1: 14Syringa vulgans ’Krasavitsa Moskvy’

4: inside back cover

Syzygium 3: 4

Taiwan 1: 20-21, 35- conifers of 1: 21taiwania 1: 21-22Taiwania cryptomemoides 1: 21Taxaceae 1: 24

Taxus chinensis 1 : 22-23

Taylor, George 2: 3Thoreau, Henry 2: 13Thymelaeaceae 4: 26Tomlinson, P. Barry 1: 29tree as symbol 1: 17 7tree, culture of 1: 18 8

Tripp, Kim E., "’Yoshino’: An Out-standing Cultivar of the JapaneseCedar" 4: 13-14

Tsuga 2: 34- canadensis 2: 33-34, 36- carohmana 2: 33- chinensis 2: 33-34, 38- dmersifoha 2: 33- heterophylla 2: 33- mertensiana 2: 33- sieboldn 2: 33, 34tulip poplar, American 1: 8--Chmese 1: 8

tupelo 1: 9’I’mce Told Tales 3: 29

U.S. Department of Agriculture 3:38,42

Ulmus amencana 2: 11 1- procera 2: 11 1Umi Hachiman Shr~ne 3: 36

"Using Arboreta to Teach BiologicalConcepts," Foster Levy and TimMcDowell 1: 2-12 2

Uva, Richard H., "Beach Plum: AShrub for Low-Maintenance Land-

scapes," with Thomas H. Whitlow4: 19-20

Vaccmmm angustifoha 2: 21- macrocarpon 2: 19 9- uhgmosum 3: 27- vitis-idaea var. minus 2: 18, 21, 25- - - - cvs 2: 25- - var. mtis-idaea 2: 18, 21, 25----cvs 2: 25Van Mons, Jean Baptist 2: 14-15 5Vatica 3: 3Veitch Nursery 2: 35; 3: 37, 39; 4:

9, 10"Verdant Letters: Hawthorne and

Horticulture," Marta McDowell 3:28-33

via.harvard.edu 3: 35, 42

viburnum, Chmese snowball 1: 4- fragrant snowball 1: 4- Korean spice 1: 4Viburnum x carlcephalum 1 : 4- carlesil 1 : 4- dilatatum ’Erie’ 4: inside front

cover

- macrocephalum 1: 4Vilmorin, Maurice de 4: 10 0Vitexrotundifoha 4: 8Vitis labrusca 2: 14, 17 7-vmifera 2: 14, 17 7

Ward, Alan, photos by 2: inside frontand back covers

Warnement, Judith A., "In Memori-am : Richard Alden Howard, 1917-2003," with Carroll E. Wood, Jr.2: 2-7

Washburn, Bradford 2: 3’Wayside’, Concord, MA 3: 31, 32Welch, Thomas 2: 16, 17 7Whitlow, Thomas H., "Beach Plum: AShrub for Low-Maintenance Land-

scapes," with Richard H. Uva 4:19-20

willow 3: 8-10, 13, 16, 20-21Wilson, E. H. 1: 21-23; 2: 35; 3: 34,

37-38; 4: 9, 10, 11; photos by 3: 11,37; 4: 12

wintersweet 4: 21 1

witch hazel 1 : 4, 10 0-- Chmese 1: 4

--Japanese 1: 4Wong, K. M., photo by 3: back coverWood, Carroll E. Wood, Jr. 2: 2----- "In Memonam: RichardAlden Howard, 1917-2003," withJudith A. Warnement 2: 2-7

Wynne, Wilham 4: 4

Yalu River 3: front cover, 21, 38yew 1: 17, 22- Chmese 1: 1: 22- Taiwan catkin 1: 24Ym Hung-chang 2: 2"’Yoshino’: An Outstanding Culti-var of the Japanese Cedar," Kim E.Tripp 4: 13-14

YuShan National Park [Taiwan] 1: 23

On the inside front cover, clockmse from top left: Magnolia virginiana ’Moonglow’, courtesy of Broken ArrowNursery; Betula alleghaniensis, photo by Peter Del Tredici; Viburnum dilatatum ‘Erie’, courtesy of Sprmg MeadowNursery; the habit of Betula alleghaniensis, photo by Peter Del Tredici.

On the inside back cover, clockwise from top left: Syringa vulgaris ’Krasavitsa Moskvy’, photo by John H.Alexander III, Poncirus trifoliata, the hardy orange tree, and Kalmia latifolia ’Comet’, both by Peter Del Tredici;Callicarpa dichotoma ‘Issai’, courtesy of Spring Meadow Nursery.